figures



March 31, 1964 w. B. CRANE 3,127,086

SHIPPING CONTAINER Filed April 18, 1963 3 Sheets-Sheet 1 INVENTOR' W94 T0/\/ .5 CeAA/E BYMW mm ATTORNE Y5 March 31, 1964 w. B. CRANE 3,127,086

SHIPPING CONTAINER Filed April 18, 1963 3 Sheets-Sheet 2 W44 TON 5. CQ/Q/VE M Wad/m ATTORNEYS March 31, 1964 Filed April 18, 1963 W. B. CRANE SHIPPING CONTAINER 3 Sheets-Sheet 3 United States Patent 3,127,086 SHIPPIIQG CONTAINER Walton B. Crane, South Pasadena, Calif., assignor to Allied Plastics Company, Los Angeles, Calif, a corporation of California Filed Apr. 18, 1963, Ser. No. 273,894 4 Claims. (Cl. 229-27) The present invention relates to improvements in shipping containers and is more particularly concerned with improvements in a tray-type container fabricated from a suitable reinforced paperboard stock, preferably corrugated board, which is particularly adapted for shipping fruits, vegetables and other produce.

This application is a continuation-in-part of application Serial No. 90,359, filed February 20, 1961, now abandoned.

It is a general object of the invention to provide a paperboard tray-type shipping container or produce crate which is fabricated from corrugated paperboard stock and which is so constructed that it has adequate strength, rigidity and resistance to crushing when a multiplicity of trays or crates are stacked in vertically disposed relation.

It is a more specific object of the invention to provide a tray-type produce shipping container fabricated from corrugated board stock which is cut, creased or scored, and folded to provide side Walls and end walls upstanding from a bottom wall and a multiple panel cross partition with the cross partition panels folded about a top crease line into inverted V-shaped relation and glued or otherwise secured to the bottom wall.

It is a further object of the invention to provide a traytype produce shipping container formed from corrugated board material which is cut and creased to provide, when set up, a bottom wall, side walls, multiple thickness end walls, and a medial cross partition which comprises a pair of panels folded about a top edge forming crease into inverted V-shaped relation and having glue flaps of substantial length extending along the bottom edge which glue flaps project through a cross slot in the bottom wall and are folded in opposite directions and adhered to the bot tom surface of the bottom wall so as to provide a rigid cross partition which is permanently secured to the bottom Wall thereby affording substantial resistance against transverse and vertical stresses.

It is another object of the invention to provide a traytype produce shipping container which is formed from corrugated paperboard material and which comprises, when set up, a bottom wall, side walls and end walls upstanding from the bottom wall, and a medial cross partition formed by a pair of panels integrally connected along their top edges and folded into inverted V-shaped relation, the panels being connected to the side Walls and each of the panels having hinged along an intermediate portion of its bottom edge one or more glue flaps of substantial length, which glue flaps project through cross slots provided in the bottom wall and are folded over and adhered to the bottom surface of the bottom wall so as to provide a rigid cross partition extending between the side Walls which is permanently secured to the bottom wall.

It is still another object of the invention to provide a tray-like produce shipping container or crate which is fabricated from paperboard material cut and creased so as to provide a series of panels which form, in the erected container, a bottom wall, side walls hinged to the side edges of the bottom wall, end Walls extending between opposite edges of the side walls, and a transverse partition intermediate the ends of the side walls, which transverse partition comprises a pair of panels integrally connected along a top edge forming hinge crease and folded downwardly so as to bring their adjoining faces into confront- 3,1Z7fi86 Patented Mar. 31, 1964 ing relation and having narrow flaps of substantial length hinged to their free edges, the bottom wall having elongated cross slots for receiving the flaps, with the edge portions of the panels adjoining the flaps abutting the in side surfaces of the bottom wall, and with the flaps being folded against and permanently secured to the outside surface of the bottom wall whereby the bottom of the cross partition is connected in rigid relation to the bottom wall and the bottom wall is held against downward bowing.

These and other objects and advantages of the invention will be apparent from a consideration of the several forms of the shipping tray or crate which are shown by way of illustration in the accompanying drawings wherein:

FIGURE 1 is a top perspective view of a produce shipping container or crate which is constructed in accordance with the principles of the invention;

FIGURE 2 is a top plan view of a paperboard blank employed in fabricating the crate of FIGURE 1;

FIGURE 3 is a top plan view, to an enlarged scale, of a crate formed from the blank of FIGURE 2, in partially set up condition;

FIGURE 4 is a fragmentary bottom view of the crate;

FIGURE 5 is a fragmentary longitudinal sectional to an enlarged scale, taken on the line 55 of FIGURE 1;

FIGURE 6 is a fragmentary top plan view of a modified form of the crate;

FIGURE 7 is a perspective view of another modified form of the crate; and

FIGURE 8 is a plan view of a paperboard blank employed in fabricating the crate in FIGURE 7.

Referring to the drawings, the tray or crate which is illustrated in FIGURES l to 5 is fabricated from a single blank 10 of generally rectangular shape which is out and scored or creased as illustrated in FIGURE 2. The cut and scored blank 10 is symmetric about a horizontal, longitudinally extending, medial line aa except for certain panel locking elements which will be hereinafter described. Accordingly, for simplicity, the same reference numerals will be employed to designate corresponding parts and/ or relationships on one side of the medial line a-a while the same numerals primed will be employed to designate like parts on the opposite side of the medial line a-a. The locking elements for the bottom forming panels are not symmetric about the medial line a-a but corresponding elements are arranged in diagonally opposite relation at opposite ends of the blank, in a manner which will be described.

The blank 10 is divided by longitudinally spaced, transversely extending crease lines into a central partition and end wall forming section 11, adjoining side and end wall or corner connecting flap forming sections 12, and bottom and end wall panel forming sections 13 at opposite ends of the blank.

The side Wall and corner connecting flap forming sections 12 are subdivided into side wall forming panels 14 which are separated from the central partition and end wall forming section '11 by short hinge forming crease lines 15 and 16, the latter being aligned transversely and spaced longitudinally of the blank 10. The side wall panels 14 are provided at their opposite ends with end Wall or corner connecting flaps 17 and 17 which are separated therefrom by longitudinally extending hinge creases 1 8 and 18. The end Wall flaps 17, 17' are separated from adjoining outer end wall forming panels 19 and 19 at opposite sides of the central partition and end wall forming section 11 by transversely extending cutting lines 20 and 20' with the latter being in transverse alignment with the crease lines 15, '16 and with the end wall panels 17 and 17 each having cut out side portions 21 and 2d. The outer end wall forming panels '19 and 1 are separated from the central portion of the center section 11 by longi- .tudinally extending crease lines 22 and 22' which are spaced outwardly slightly of the adjacent longitudinally extending crease lines 13 and 18.

The two bottom wall forming sections 13 at opposite ends of the blank are subdivided to provide bottom wall forming panels 23 which are separated from the adjoining side wall forming panels 14 by transversely extending crease lines 24. The bottom wall forming panels 23 are each provided with end wall forming flaps 25, 25' at opposite sides of the blank which flaps are separated from the bottom wall forming panels 23 by longitudinally extending crease lines 26, 26', the latter being offset outwardly relative to the adjacent longitudinal crease lines 18 and 1 8. The end Wall forming flaps 25, 25 are separated from the adjoining end wall or corner connecting flaps 17, 17 by cutting lines 27, 27 and the edge portion of each fiap 17, 17 is cut away at 28, 28'. Each bottom wall panel 23 is provided along its outer free edge, which constitutes the end edge of the blank 10, with a pair of locking tongue elements or formations 29 and 30 which are spaced transversely and project in the longitudinal direction of the blank with respective tongues on each panel 23 being diagonally opposite the corresponding tongue on the other panel 23 and having identical end locking tabs 31 which are separated from the panels 23 by a locking slot 32 and which face in the same direction with the tabs at opposite ends of the blank facing oppositely relative to the end wall forming flaps 25, 25'. Each of the bottom forming panels 23 is also provided with a generally rectangular cross partition latching slot 33 straddling the medial line a-a. The slots 33 extend in parallelism with the line aa and are located so that they fall in the middle of the crate when the latter is set up so as to form a single elongate slot. The bottom wall forming panels 23 are cut out or slotted at 35, 35' at the outer ends of the crease lines 26 and 26 to form, when the panels 23 have their free edges overlapped and interlocked, wire tie receiving apertures.

The central partition and end wall forming section 11 of the blank 10 is subdivided by the transversely spaced, longitudinally extending, parallel crease lines 36 and 36 which straddle the medial line aa and which form between them a relatively narrow cross partition top wall panel or edge 37. The panel sections on opposite sides of the crease lines 36 and 36' are further subdivided by longitudinally extending pairs of slitting lines 38, 39 and 38', 39 which are laterally spaced on either side of the medial crease lines 36 and 36' and which are spaced approximately the same distance from the crease lines 36, 36' and 22, 22'. The slits 38, 38 define the free edges of cross partition panels 40, 40' and inner end wall forming panels 41, 41. The cross partition panels 40, 40' are integrally hinged to the center cross partition top strip 37 on the crease lines 36 and 36'. The inner end wall forming panels 41 and 41' are integrally hinged to relatively narrow, longitudinally extending, top end wall forming sections 42 and 42 which are formed between inner hinge forming crease lines 43 and 43 and the outer crease lines 22, 22'. Tab formations 45 and 45' are provided on the hinged edges of the inner end wall panels 41 and 41 by generally U-shaped cutting lines 46 and 46' in the center of the top wall sections 42 and 42 which have their legs terminating at the inner crease lines 43 and 43' and which extend slightly into the adjoining outer end wall forming panels '19 and 19'. The cross partition panels 40, 40' and the inner end wall panels 41, 41 are separated from the side wall panels 14 by elongate slots 47, 47 and 48, 48 extending into the side wall panels and by diagonally extending slits 49, 49' and 50, 50'. The slits 50, 50' extend from the outer ends of the slots 47, 47 and 48, 48' to the inner end wall crease lines 43, 43 of the panels 41, 41 while the slits 49 and 49' extend from the inner ends of the slots 47, 47' to the medial crease lines 36, 36'. The slots 47, 47 and 48, 48' and the slits 49, 49' and 50, 50 are so arranged that they free the ends of the panels 40, 4d and 41, 41 for hinging movement about the crease lines 36, 36 and 43, 43. This leaves the outer end wall panels :19 and 19 connected at their opposite ends to the side wall panels 14 by the triangular connecting web portions 5 1 and 51. The slits 49, 49 are on diagonally opposite sides of the cross partition top edge strip 37 and at opposite ends of the latter so that each cross partition panel 40, 40 is connected to the top edge strip 37 and to the adjacent side wall panel 14 by a triangular web formation 52, 52. Each cross partition forming panel 40, 40' is provided at its edge 38, 38' with a glue flap 53, 53' which are adapted to hinge about the score lines 54, 54', the latter being aligned with the cutting lines 38, 38 and the glue flaps 53, 53 extending a substantial distance so that their length is approximately onethird the distance between the spaced transverse crease lines 15, 16. The inner end wall forming panels 41 and 41 are provided at their inner edges with locking tongues 57 and 57'.

In setting up the tray or crate, the cut and creased blank 10 is folded into tubular form by hinging the side wall panels 14 about the crease lines 15, 16 and the bottom wall panels 23 about the crease lines 24 to bring the locking tongues 29 and 30 on the free edges thereof into overlapping or interengaging relation with the marginal portions of the panels 23 and interlocking the same by interengaging the tabs 31 and slots 32 on the respective pairs of tongues 29 and 30. The end wall forming flaps 17, 17 on the side wall panels 14 are then folded inwardly about the crease lines 18, 1 8" and the end wall fiaps 25, 25' of the bottom Wall forming panels 23 are thereafter folded into upstanding relation about the crease lines 26, 26'. The flaps 17, 17 preferably have an adhesive applied to their bottom faces so that they are adhesively secured to the inner faces of the end wall flaps 25, 25. The outer end wall flaps 19 and 19 are folded about the crease lines 2 2, 22. against the end wall flaps 25, 25' with an adhesive being applied between the same to adhere the inner engaging faces to each other. Thereafter, the inner end wall panels 41 and 41' are folded downwardly about the crease lines 43, 43 to bring the end locking tongues 58, 58' thereon into the openings in the bottom which are formed by the slots 35, 35 in the panels 23. This operation completes the end walls.

The cross partition forming panels 40, 40' are then folded downwardly about the hinge lines 36, 36 and the marginal flaps 53, 53 are passed through the elongate transverse slot 33 and folded in opposite directions into engagement with the lower faces of the bottom wall panels after an adhesive has been applied to the flaps 53, 53 so as to secure the same in connected relation with the bottom wall. The two cross partition panels 40, 40' form an inverted V-shaped strut between the side walls 14 which is rigidly connected to the bottom wall and which resists stresses both transversely and vertically.

.A modified form of cross partition is illustrated in FIGURE 6. The crate outside walls are the same as in the form shown in FIGURES 1 to 5 except for the omission of the slot 33 in the bottom wall. The cross partition panels and 140 are formed in the same manner as panels 40 and 40 except for the bottom edge flaps 153 and 15 3 which are extended along the bottom edges of the panels 140 and 140 and scalloped as indicated. The flaps 153 and 153' are folded against the inside surfaces of .the bottom wall panels and adhesively secured. The scalloping provides faster setting up of the glue and also requires a smaller quantity of glue than with a solid flap. The length of the flaps may, of course, be varied, if desired.

The scalloping feature illustrated in FIGURE 6 may be employed in the form of the crate which is illustrated in FIGURES 1 to 5, that is, the marginal flaps 53 and 53' may be scalloped in the same manner as the flaps 153 and 153 to provide for faster setting of the glue and also greater economy.

A modified form of the crate is illustrated in FIGURES 7 and 8 which incorporates the invention. The blank 210 from which this crate is formed is to a large extent identical with the blank 10* illustrated in FIGURE 2 and corresponding panels, crease lines and cutting lines will be identified by the same numerals plus 204). Only those elements which are structurally different will be described in detail. The blank 21d is cut and scored as shown in FIGURE 8 to provide a central partition and end wall forming section 211, adjoining side and end wall corner connecting flap forming sections 212 and bottom and end wall forming sections 213 at opposite ends of the blank. The side wall and corner connecting flap forming sections 212 and the two bottom wall forming sections 213 at opposite ends of the blank 210 are cut and creased in the same manner as in the blank 11 except that the slots 233 in the bottom wall panels 223 are cut (as shown in FIG- URE 8) so that they are shorter than the slots 33' in the panels 23 and each slot is located wholly within the body of the panel 223 so that it extends transversely of the panel 223 and intermediate the side edges thereof. The central portition and end wall forming section 21-1 of the blank 210 is cut and creased in the same manner as section 1-1 of the blank it) except for the cross partition panels 244} and -24t which are cut on the slitting lines 233 and 238, so as to provide pairs of glue flaps 253, 253 and 253, 253 with the flaps of each pair thereof spaced equal distances from the center of the slitting line 238 or 238'. The flaps 253 and 253- of each pair thereof are of substantial length, but the lengthwise dimension is less than the corresponding dimension of the glue flaps 53 and 53. All other elements of the blank 210' are identical with the corresponding elements of the blank it In setting up the crate or tray as shown in FIGURE 7, the cut and creased blank 21%) is folded and the respective panels are connected in the same manner as described in connection with the crate of FIGURE 1. The pairs of glue flaps 253 and 253' on the free edges of the cross partition panels 249 and 240 are passed through the slots 233 in the bottom wall panel 223 and folded, preferably in the direction of the end walls, into engagement with the lower faces of the bottom wall panel after an adhesive has been applied to the flaps 253, 253 so as to secure the same thereto and provide a rigid connection between each of the two panels of the bottom wall and the two cross partition panels. The two cross partition panels 24% and 240' form an inverted V-shaped strut between the side walls 214 which is rigidly connected to each of the bottom wall panels 223 with the lower edges of the cross partition panels which adjoin the flaps 253 and 253 abutting the inside surfaces of the bottom wall panels. The cross partition panels support the bottom wall panels and prevent bowing thereof when the crate is filled with produce.

While the crates in FIGURES 1 and 7 are shown fabricated with a two panel bottom wall, these crates could be produced with a single panel bottom wall having a single central slot for accommodating relatively long connecting glue flaps on the cross partition panels as in the crate of FIGURE 1 or having a pair of transversely spaced slots accommodating pairs of shorter glue flaps as in the crate of FIGURE 7.

While particular materials and specific details of construction have been referred to in describing the several forms of the tray illustrated, it will be understood that other materials and different details of construction may be resorted to within the spirit of the invention.

1 claim:

1. A tray-like container which is fabricated from paperboard material and which comprises when erected, a bottom wall, side walls hinged to the side edges of the bottom wall, end walls extending between opposite ends of the side walls, and a transverse partition intermediate the ends of the side walls, said end walls each comprising inner and outer end Wall forming panels which are downby triangular corner webs in the plane of the top wall which are hinged to the end wall and side wall panels on transverse and longitudinal creases, respectively, and end wall forming flaps which are hinged to the ends of the bottom wall and turned upwardly of said bottom wall between said downwardly hinged inner and outer end wall forming panels, means securing said end wall flaps in rigid relation with said outer end wall panels, and said transverse partition comprising a pair of panels integrally hinged to a top edge forming cross partition strip extending in the plane of the top wall and at right angles to said side wall panels and being hinged downwardly so as to form a cross strut of inverted V-shape, said cross partition panels being connected to the side Wall forming panels by triangular webs in the plane of the top wall which are hinged to said cross partition panel and said side wall panels on transverse and longitudinal crease lines, said pair of cross partition panels having relatively narrow integral glue flaps of substantial length hinged to their free edges, said bottom wall having an elongate cross slot, said cross partition panels having edge portions adjoining said flaps abutting the inside surfaces of said bottom wall, said glue flaps extending through said cross slot and being folded over and adhesively secured in fixed relation on the outside surface of the bottom wall so as to rigidly connect the bottom of the cross partition and the bottom wall.

2. A tray-like container which is fabricated from a paperboard blank, said blank being cut and creased to divide the same into a series of integrally connected panels which form, in the erected container, a bottom wall comprising two panels having overlapped margins at the lon gitudinal center of the container, side walls hinged to the side edges of the bottom wall, end walls extending between opposite ends of the side walls, and a transverse partition intermediate the ends of the side walls, said end walls each comprising inner and outer end wall forming panels which are hinged downwardly from a relatively narrow top end wall strip extending in the plane of the top wall between the top edges of the side walls, the outer one of said end wall forming panels being connected to the side wall forming panels by corner webs in the plane of the top wall which are hinged to the end wall and side wall panels, and end wall forming flaps hinged to the ends of the bottom wall and disposed in upturned relation to said bottom wall between said downwardly hinged inner and outer end wall forming panels, said end wall flaps and said outer end wall panel being secured in rigid relation to each other, and said transverse partition comprising a pair of panels integrally hinged to a top edge forming cross partition strip extending between and at right angles to said side wall panels and being hinged downwardly so as to bring their adjoining faces into confronting relation, said pair of cross partition panels having relatively long, narrow flaps hinged to center portions of their free edges, said bottom wall panels having an elongate cross slot extending across their overlapped margins for receiving said flaps, said panels having edge portions adjoining said flaps abutting the inside surfaces of said bottom wall panels, said flaps extending through the cross slot and being folded in opposite directions against the outside surfaces of said bottom wall panels and said flaps being permanently secured to said bottom wall panel surfaces so as to connect the bottom of the cross partition in rigid relation to the bottom wall panels and hold said panels against downward bowing.

3. A tray-like container which is fabricated from paperboard material which is cut and creased to provide a series of connected panels which form, in the erected container, a bottom wall comprising two panels having overlapped margins at the longitudinal center of the container, side walls hinged to the side edges of the bottom wall, end walls extending between opposite ends of the side Walls, and a transverse partition intermediate the ends of the side walls, said end walls each comprising inner and outer end wall forming panels which are hinged downwardly from a relatively narrow top end wall strip extending in the plane of the top wall between the top edges of the side walls, the outer one of said end wall forming panels being connected to the side wall forming panels by corner webs in the plane of the top wall which are hinged to the end wall and side wall panels, and end wall forming flaps hinged to the ends of the bottom wall and disposed in upturned relation to said bottom wall between said downwardly hinged inner and outer end wall forming panels, said end wall flaps and said outer end wall panel being secured in rigid relation to each other, and said transverse partition comprising a pair of panels integrally hinged to a top edge forming cross partition strip extending between and at right angles to said side wall panels and being hinged downwardly so as to bring their adjoining faces into confronting relation, said pair of cross partition panels having relatively narrow flap members of substantial length hinged to their free edges, said bottom wall panels having elongated cross slots in the areas between their side edges for receiving said narrow flap members, said cross partition panels having edge portions adjoining said flap members which abut the inside surfaces of said bottom wall panels, said flap members extending through the cross slots and being folded against the outside surfaces of said bottom wall panels and said flap members being permanently secured to said bottom wall panel surfaces so as to connect the bottom of the cross partition in rigid relation to the bottom wall panels and hold said bototm wall panels against downward bowing.

in t

4. A tray-like container which is fabricated from paperboard material cut and creased to provide a series of connected panels which form, in the erected container, a bottom wall, side walls hinged to the side edges of the bottom wall, end walls extending between opposite ends of the side walls, and a transverse partition intermediate the ends of the side walls, said end walls each comprising inner and outer end wall forming panels which are hinged downwardly from a relatively narrow top end wall strip extending in the plane of the top wall between the top edges of the side walls, the outer one of said end wall forming panels being connected to the side wall forming panels by corner webs in the plane of the top wall which are hinged to the end wall and side wall panels, and end wall forming flaps hinged to the bottom wall disposed in upturned relation to said bottom wall between said downwardly hinged inner and outer end wall forming panels, said end wall flaps and said outer end wall panel being secured in rigid relation with each other, and said transverse partition comprising a pair of panels integrally hinged to a narrow top edge forming cross partition strip extending in the plane of the top wall and at right angles to said side wall panels and being hinged downwardly so as to form a double panel cross strut, said pair of cross partition panels having relatively long narrow integral flap members hinged to the center portions of their free edges, said bottom wall having an elongate cross slot for receiving said flap members, said panels having edge portions adjoining said flaps abutting the inside surfaces of said bottom wall, said flap members extending through said slot and being folded over upon and adhesively secured to the bottom surface of the bottom walls so as to rigidly connect the bottom wall and the cross partition and hold the bottom wall against downward bowing.

No references cited. 

1. A TRAY-LIKE CONTAINER WHICH IS FABRICATED FROM PAPERBOARD MATERIAL AND WHICH COMPRISES WHEN ERECTED, A BOTTOM WALL, SIDE WALLS HINGED TO THE SIDE EDGES OF THE BOTTOM WALL, END WALLS EXTENDING BETWEEN OPPOSITE ENDS OF THE SIDE WALLS, AND A TRANSVERSE PARTITION INTERMEDIATE THE ENDS OF THE SIDE WALLS, SAID END WALLS EACH COMPRISING INNER AND OUTER END WALL FORMING PANELS WHICH ARE DOWNWARDLY HINGED FROM A RELATIVELY NARROW TOP END WALL STRIP EXTENDING IN THE PLANE OF THE TOP WALL AND BETWEEN THE TOP EDGES OF THE SIDE WALLS, ONE OF SAID END WALL FORMING PANELS BEING CONNECTED TO THE SIDE WALL FORMING PANELS BY TRIANGULAR CORNER WEBS IN THE PLANE OF THE TOP WALL WHICH ARE HINGED TO THE END WALL AND SIDE WALL PANELS ON TRANSVERSE AND LONGITUDINAL CREASE, RESPECTIVELY, AND END WALL FORMING FLAPS WHICH ARE HINGED TO THE ENDS OF THE BOTTOM WALL AND TURNED UPWARDLY OF SAID BOTTOM WALL BETWEEN SAID DOWNWARDLY HINGED INNER AND OUTER END WALL FORMING PANELS, MEANS SECURING SAID END WALL FLAPS IN RIGID RELATION WITH SAID OUTER END WALL PANELS, AND SAID TRANSVERSE PARTITION COMPRISING A PAIR OF PANELS INTEGRALLY HINGED TO A TOP EDGE FORMING CROSS PARTITION STRIP EXTENDING IN THE PLANE OF THE TOP WALL AND AT RIGHT ANGLES TO SAID SIDE WALL PANELS AND BEING HINGED DOWNWARDLY SO AS TO FORM A CROSS STRUT OF INVERTED V-SHAPE, SAID CROSS PARTITION PANELS BEING CONNECTED TO THE SIDE WALL FORMING PANELS BY TRIANGULAR WEBS IN THE PLANE OF THE TOP WALL WHICH ARE HINGED TO SAID CROSS PARTITION PANEL AND SAID SIDE WALL PANELS ON TRANSVERSE AND LONGITUDINAL CREASE LINES, SAID PAIR OF CROSS PARTITION PANELS HAVING RELATIVELY NARROW INTEGRAL GLUE FLAPS OF SUBSTANTIAL LENGTH HINGED TO THEIR FREE EDGES, SAID BOTTOM WALL HAVING AN ELONGATE CROSS SLOT, SAID CROSS PARTITION PANELS HAVING EDGE PORTIONS ADJOINING SAID FLAPS ABUTTING THE INSIDE SURFACES OF SAID BOTTOM WALL, SAID GLUE FLAPS EXTENDING THROUGH SAID CROSS SLOT AND BEING FOLDED OVER AND ADHESIVELY SECURED IN FIXED RELATION ON THE OUTSIDE SURFACE OF THE BOTTOM WALL SO AS TO RIGIDLY CONNECT THE BOTTOM OF THE CROSS PARTITION AND THE BOTTOM WALL. 